CryptoHack
A fun, free platform for learning modern cryptography
Learn By Doing
Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.
Level Up
Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?
Fresh Challenges
We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.
New Challenges
| Blind (ECSC 2023 (Norway)) | CTF Archive | 0 |
| WOTS Up (ECSC 2023 (Norway)) | CTF Archive | 0 |
| Irish flan (ECSC 2023 (Norway)) | CTF Archive | 0 |
| WOTS Up 2 (ECSC 2023 (Norway)) | CTF Archive | 0 |
| Twist and shout (ECSC 2023 (Norway)) | CTF Archive | 0 |
Weekly Top Users
| #1 | Joe_syn | 5575 |
| #2 | dys4nt | 4095 |
| #3 | Tt123N | 3285 |
| #4 | AdityaDuggal | 3215 |
| #5 | Manav11 | 3010 |
Recent Solves
| You either know, XOR you don't | K55A | |
| Extended GCD | kodeythomas | |
| Lazy CBC | Skinbow | |
| Script Kiddie | ThinkInTheBox | |
| Finding Flags | smallfry |
Recent Solutions
| Modular Arithmetic 1 | werePhilosoper | 0 |
| Extended GCD | werePhilosoper | 0 |
| Null or Never | twelho | 0 |
| Passwords as Keys | Ubertech | 0 |
| Broken RSA | zenobia | 1 |